Investigations on the Fluorescence Concentration Quenching of Flavomononucleotide in Glycerine‐water Solutions

Abstract

We measured concentration changes of the fluorescence quantum yield eta/eta 0 of flavomononucleotide (FMN) in glycerine-water solutions of various viscosities. The results obtained show that FMN dimers are traps for the exciting light energy as well as the energy transferred non-radiatively. Very good agreement between the experimental and theoretical eta/eta 0 results was obtained. It has been shown that in the investigated solutions non-radiative energy transfer from monomers to dimers takes place, preceded by the migration of energy. It has been stated that no monomer quenching occurs in these solutions. The contribution of the individual fluorescence concentration quenching mechanisms has been determined.

Resonance energy transfer between FMN molecules in the presence of dimers: A review

“…(10) and (11)) for the description of concentration dependent data of fluorescence quantum yield and emission anisotropy of FMN in glycerol-water solutions of different viscosities η′ = 0.056 Pa s (GWI) and 0.256 Pa s (GWII) has shown that multistep energy transfer takes place in the monomer and dimer systems [69,70]. The excitation energy can visit different monomers M* prior its transfer to FMN dimers D:…”

“…The first reports on qualitative and quantitative properties of energy transport for FMN appeared in 1990 and were based on the Bojarski theory of multistep excitation energy transfer: the theory of photoluminescence concentration quenching (PLCQ) [69] and the theory of concentration depolarization of photoluminescence (CDPL) [70]. Table 2).…”

“…The investigations on the concentration changes of fluorescence quantum yield of FMN in liquid solutions [69], the emission anisotropy [70], and the excitation-emission spectra of FMN [73] have shown that FMN dimers are non-fluorescent and they are perfect traps for the exciting light energy as well as the energy transferred nonradiatively. However, in rigid solutions, the FMN dimers become fluorescent and may take part in energy transfer [36,74,73,37].…”

“…In water, the solubility of FMN reaches 8 × 10 −2 M, but in investigations of FMN in water the following range of concentrations was used: from C = 1 × 10 −5 M to 1.8 × 10 −2 M (in publications [62,64,35,68]). However, the solubility of FMN in the glycerol-water (GW) solution and in PVA is higher, so C max = [ [50][51][52] 9 × 10 −2 M was used for GW solution [64,69,70] and C max = 1 M for PVA [61,36].…”

“…The resonance energy transfer and energy migration between FMN molecules were widely examined in water [68], viscous [69,70] and rigid solutions [36,37,82,83].…”